Phase equilibria and electrical properties of Nd2O3-SrO-TiO2 system

１ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｃｏｎｎｅｃｔｉｏｎｗｉｔｈｏｕｒｒｅｓｅａｒｃｈｏｎｔｅｒｎａｒｙｃｏｍｐｏｕｎｄｕｓｅｄｆｏｒｄｉｅｌｅｃｔｒｉｃｍａｔｅｒｉａｌ,ｔｈｅｓｙｓｔｅｍｏｆＮｄ２Ｏ３ＳｒＯＴｉＯ２ｗａｓｉｎｖｅｓｔｉｇａｔｅｄ．ＯｔｈｅｒｔｈａｎｓｏｍｅｃｏｍｐｏｕｎｄｓｒｅｐｏｒｔｅｄｂｙＳｉｄｏｒｏｖａ［１］,ｔｈｉｓｓｙｓｔｅｍｈａｓｎｏｔｂｅｅｎｒｅｐｏｒｔｅｄｓｙｓｔｅｍａｔｉｃａｌｌｙ．Ｏｕｒｓｐｅｃｉａｌｉｎｔｅｒｅｓｔｆｏｃｕｓｅｄｏｎｔｈｅｐｒｏｂｌｅ…     

Molecular dynamics of structural properties of molten CaO-SiO2 with varying composition

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｓｔｕｄｙｏｆｍｏｌｔｅｎｓｔｒｕｃｔｕｒｅｏｆＣａＯ ＳｉＯ2 ,ｗｈｉｃｈａｃｔａｓｔｈｅｂａｓｉｃｆａｃｔｏｒｉｎｆｌｕｅｎｃｉｎｇｔｈｅｐｈｙｓｉｃａｌａｎｄｃｈｅｍｉｃａｌｐｒｏｐｅｒｔｉｅｓｏｆｔｈｅｓｉｌｉｃａｔ     

Leaching behavior of butanedionedioxime as gold ligand

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒｅａｒｅｔｗｏｔｙｐｅｓｏｆｏｒｂｉｔａｌｓｉｎｏｕｔｅｒｅｌｅｃｔｒｏｎｏｒｂｉｔａｌｓｏｆｇｏｌｄａｎｄｉｔｓｌｉｘｉｖｉａｎｔｓ[1,2 ] .ＯｎｅｉｓｃａｌｌｅｄＨＯＥＯ(ｈｉｇｈｅｒｏｃｃｕｐｉｅｄｅｌｅｃｔｒｏｎｉｃｏｒｂｉｔａｌｓ) ,ｓｕｃｈａｓπ ｔｙｐｅＨＯＥＯｏｆｂｏｔｈ 5ｄ2(ｘ2 -ｙ2 ) ａｎｄ 5ｄ2ｚｏｆｇｏｌｄ ,ａｎｄσ ｔｙｐｅＨＯＥＯｏｆσ22 ｐｘｏｆｃｙａｎｉｄｅ;ａｎｄａｎｏｔｈｅｒｃａｌｌｅｄＬＵＥＯ(ｌｏｗｅｒｕｎｏｃｃｕｐｉｅｄｅｌｅｃｔ…     

Kinetic mechanism of anodic oxidation of tantalum in nitrate melts

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴａｎｔａｌｕｍｃａｎｂｅｏｘｉｄｉｚｅｄａｔｌｏｗｔｅｍｐｅｒａｔｕｒｅｉｎ ｔｏｉｎａｃｔｉｖｅＴａ2 Ｏ5 ｗｉｔｈｃｏｍｐａｃｔｔｅｘｔｕｒｅａｎｄｓｐｅｃｉｆｉｃｒｅｓｉｓｔａｎｃｅｏｆ 1 0 18Ω·ｃｍ[1],ｗｈｉｃｈｅｎｔｉｔｌｅｓｔａｎｔａｌｕｍｇｏｏｄｃｏｒｒｏｓｉｏｎｒｅｓｉｓｔａｎｃｅａｎｄｅｌｅｃｔｒｉｃｒｅｓｉｓｔａｎｃｅ ,ａｎｄａｌｓｏｍａｋｅｓｉｔｉｍｐｏｓｓｉｂｌｅｔｏｇｅｔｔｈｉｃｋＴａ2 Ｏ5 ｆｉｌｍｓａｔｌｏｗｔｅｍｐｅｒａｔｕｒｅ .Ｔｈｅｏ…     

Study on electrochemical surface modification of coal by FTIR and Raman spectra

1　ＩＮＴＲＯＤＵＣＴＩＯＮＨｉｇｈｓｕｌｆｕｒｃｏａｌｏｃｃｕｐｉｅｓａｌａｒｇｅ ｐａｒｔｏｆｔｈｅｗｈｏｌｅｄｅｐｏｓｉｔｏｆｃｏａｌｉｎｔｈｅＳｏｕｔｈ ＷｅｓｔａｎｄｔｈｅＥａｓｔｏｆＣｈｉｎａ .Ｗｉｔｈｏｕｔｗａｓｈｉｎｇａｎｄｄｅｓｕｌｆｕｒｉｚａｔｉｎｇ ,ｔｈｅｃｏｍｍｅｒｃｉａｌｃｏａｌｉｓｏｆｌｏｗｑｕａｌｉｔｙ ,ｌｏｗｃｏｍｂｕｓｔｉｏｎｅｆ ｆｉｃｉｅｎｃｙｗｉｔｈｌａｒｇｅｃｏａｌｗａｓｔｉｎｇ ,ｇａｓａｓｈ ,ＣＯ2 ａｎｄＮＯｘ .Ａｂｏｖｅａｌｌ,ｔｈｅｃｏｍｂｕｓｔｉｏｎ…     

Formation mechanism of laser-clad gradient thermal barrier coatings

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＺｒＯ2 ｃｅｒａｍｉｃｓｗａｓｓｅｌｅｃｔｅｄａｓｔｈｅｍａｔｅｒｉａｌｏｆｔｈｅｒｍａｌｂａｒｒｉｅｒｃｏａｔｉｎｇｓ (ＴＢＣｓ)ｆｏｒｉｔｓｈｉｇｈｍｅｌｔ ｉｎｇ ｐｏｉｎｔａｎｄｈｉｇｈｅｘｐａｎｓｉｏｎｃｏｅｆｆｉｃｉｅｎｔ[1].ＴｈｅｍｅｔｈｏｄｔｏｐｒｏｄｕｃｅＴＢＣｓｗａｓｕｓｕａｌｌｙｐｌａｓｍａｓｐｒａｙｉｎｇｔｅｃｈｎｉｑｕｅ.Ｔｈｅｐｏｒｏｓｉｔｙｉｎｔｈｅｃｏａｔｉｎｇａｎｄｔｈｅｐｏｏｒａｄｈｅｒｅｎｃｅｂｅｔｗｅｅｎｃｏａｔｉｎｇａｎｄｓ…     

ASTUDY OF VALENCE OF YTTRIUM IN Y_2O_3 Mo CATHODE

１．ＩｎｔｒｏｄｕｃｔｉｏｎＡｓａｎｅｗｋｉｎｄｏｆｒａｒｅｅａｒｔｈｍｏｌｙｂｄｅｎｕｍｃａｔｈｏｄｅｍａｔｅｒｉａｌ,ＭｏＹ２Ｏ３ｉｓｅｘｐｅｃｔｅｄｔｏｓｕｂｓｔｉｔｕｔｅｒａｄｉｏａｃｔｉｖｅＷＴｈＯ２ｃａｔｈｏｄｅｍａｔｅｒｉａｌｓｉｎｔｈｅｆｕｔｕｒｅ．Ｍｏ４ｗｔ％Ｙ２Ｏ３ａｌｌｏｗｓ,ｒｅｌａｔｉｖｅｔｏＭｏＬａ２Ｏ３〔１２〕（ｗｈｉｃｈｈａｓｂｅｅｎｗｉｄｅｌｙｓｔｕｄｉｅｄｓｉｎｃｅ１９７０ｓｉｎｏｒｄｅｒｔｏｓｕｂｓｔｉｔｕｔｅＷＴｈＯ２ｃａｔｈｏｄｅｍａｔｅｒ…     

Influence of doped Ag+ on multifunction characteristics in SrTiO3 ceramics

1　ＩＮＴＲＯＤＵＣＴＩＯＮＳｒＴｉＯ3 ｂａｓｅｄｍｕｌｔｉｆｕｎｃｔｉｏｎｃｅｒａｍｉｃｓｉｓａｋｉｎｄｏｆｎｅｗｓｅｍｉｃｏｎｄｕｃｔｏｒｃｅｒａｍｉｃｓｗｉｔｈｔｈｅｄｕａｌｆｕｎｃｔｉｏｎｓｏｆｃｅｒａｍｉｃｓｇｒａｉｎ ｂｏｕｎｄａｒｙ ｌａｙｅｒ(ＧＢＬ)ｃａｐａｃｉｔｏｒｏｆｈｉｇｈｃａｐａｃｉｔａｎｃｅａｎｄｖａｒｉｓｔｏｒ,ｗｈｉｃｈｅｘｈｉｂｉｔｓｃｏｎｓｉｄ ｅｒａｂｌｅｖａｌｕｅｏｆｆｕｒｔｈｅｒｒｅｓｅａｒｃｈａｎｄｒｅｍａｒｋａｂｌｅｐｏｔｅｎ ｔｉａｌｏｆｂｅｉｎｇｗｉｄｅ…     

Simulation of droplet transfer process and current waveform control of CO_2 arc welding

1　ＩＮＴＲＯＤＵＣＴＩＯＮＣＯ2 ｓｈｉｅｌｄｅｄａｒｃｗｅｌｄｉｎｇｉｓｏｎｅｏｆｔｈｅｗｅｌｄｉｎｇｔｅｃｈｎｏｌｏｇｉｅｓｗｉｔｈｈｉｇｈｅｒｅｆｆｉｃｉｅｎｃｙ ,ｌｏｗｅｒｅｎｅｒｇｙｃｏｎｓｕｍｐｔｉｏｎ ,ｌｅｓｓｈｙｄｒｏｇｅｎｃｏｎｔｅｎｔａｎｄｈｉｇｈａｎｔｉ ｏｘ ｉｄａｔｉｏｎａｂｉｌｉｔｙ .Ｔｈｅｓｈｏｒｔ ｃｉｒｃｕｉｔｔｒａｎｓｆｅｒｉｓａｍａｉｎｆｏｒｍｉｎＣＯ2 ａｒｃｗｅｌｄｉｎｇｐｒｏｃｅｓｓ ,ｂｕｔｉｔｈａｓｔｏｏｍｕｃｈｓｐａｔｔｅｒｉｎｇ ,ａｎｄｕｎｓａｔｉｓｆ…     

Influence of size of seed grains and sintering condition on varistor properties of ZnO-Bi_2O_3-TiO_2-Sb_2O_3 ceramics

1　ＩＮＴＲＯＤＵＣＴＩＯＮＳｉｎｃｅＺｎＯｖａｒｉｓｔｏｒｃｅｒａｍｉｃｓｗｅｒｅｆｉｒｓｔｌｙｄｅｖｅｌ ｏｐｅｄｉｎ 196 8,ｓｉｇｎｉｆｉｃａｎｔｐｒｏｇｒｅｓｓｅｓｈａｖｅｂｅｅｎｍａｄｅｉｎｉｎｖｅｓｔｉｇａｔｉｏｎａｎｄａｐｐｌｉｃａｔｉｏｎｏｆｔｈｅｍａｔｅｒｉａｌ.Ａｓａｋｉｎｄｏｆａｄｖａｎｃｅｄｆｕｎｃｔｉｏｎａｌｃｅｒａｍｉｃｓ,ＺｎＯｖａｒｉｓｔｏｒｃｅｒａｍｉｃｓｈａｖｅｂｅｅｎｗｉｄｅｌｙｕｓｅｄｉｎｅｌｅｃｔｒｏｎｉｃｃｉｒｃｕｉｔｓａｎｄｅｌｅｃｔｒｉｃａｌｐｏｗｅｒ…     

Cu-Sn-Pb过偏晶合金中异常Cu-Sn壳/Pb核宏观结构的形成

目前核/壳结构难混熔合金的壳是由低熔点相组成还是高熔点相组成,尚无确切答案。根据文献中Cu-Sn-Pb合金的计算相图,通过铸造法研究14Sn-73.1Cu-12.9Pb、14Sn-64.5Cu-21.5Pb、Cu-65Pb和Cu-75Pb合金的相分离过程。结果表明,14Sn-64.5Cu-21.5Pb合金具有富Cu-Sn相包裹富Pb相核/壳结构组织;这一结果与低熔点相(如Cu-75Pb合金)形成核的观点不一致,这种异常现象可以解释为:在铸造过程中,由于过冷度的影响,偏晶反应发生在液相分离反应前。这为通过控制凝固路径改变难混熔合金的结构提供了一种可能的方法。     

High-Efficiency Inhibition of Gravity Segregation in Al–Bi Immiscible Alloys by Adding Lanthanum

The inhibition of gravity segregation has been a long-standing challenge in fabrication and applications of homogeneous immiscible alloys. Therefore, the effect of rare-earth La on the gravity segregation of Al–Bi immiscible alloys was investigated to understand the homogenization mechanism. The results showed that the addition of La can completely suppress the gravity segregation. This is attributed to the nucleation of Bi-rich liquid phase on the in-situ produced LaBi₂ phase and the change of the shape of LaBi₂@Bi droplets. In addition, a novel strategy is developed to prepare the homogeneous immiscible alloys through the addition of rare-earth elements. This strategy not only is applicable to other immiscible alloys, but also is conducive to finding more elements to suppress the gravity segregation. This study provided a useful reference for the fabrication of the homogeneous immiscible alloys.     

Al-Bi-Ce-Cu难混溶合金的凝固组织和耐磨性

本文研究了Al-Bi-Ce-Cu难混溶合金的凝固组织和耐磨性能。实验结果表明,添加Ce到Al-Bi合金中,原位生成的棒状化合物Bi₂Ce作为异质形核质点,促进了Bi相的形核,所制备难混溶合金中富Bi相颗粒弥散分布。添加Cu到Al-Bi-Ce合金中生成了硬质相Al₂Cu,硬质相增强了基体的硬度,进而提高了合金的耐磨性能,降低了合金的耐磨性系数。因此Al-Bi-Ce-Cu合金,不仅具有富Bi相颗粒弥散分布的组织,同时还具有高的耐磨性能,有很强的实际应用价值。     

Miscibility gap and liquid-liquid equilibrium in the system In-Tl-Se

Electrical conductivity measurements were performed on liquid immiscible (In _x Tl_1−x )_0.80Se_0.20 alloys in a wide temperature range between 1200 K and the crystallization temperature under argon gas pressures up to 45 MPa. The electrical conductivity shows the same behavior as for binary liquid alloys during phase separation. It was revealed that variation of In-to-Tl ratio at constant Se content changes the properties of coexisting liquids and affects the phase-separation temperature T _S in a nonlinear manner. T _S varies from 1035 K for Tl_0.80Se_0.20 to 949 K for In_0.80Se_0.20 with a maximum at T _S =1061 K for In_0.22Tl_0.58Se_0.20. The results are analyzed in comparison with available data for binary and ternary immiscible alloys. The possible influence of sublattice dynamics on formation of the critical-point parameters is discussed.     

Solidification of Immiscible Alloys Under the Effect of Electric and Magnetic Fields

Immiscible alloys have aroused considerable interests in the last decades on account of their special physical and mechanical properties and potential applications. A considerable number of researches have been implemented to investigate the solidification behaviors of immiscible alloys in electric and magnetic fields. It has been indicated that the magnetic field and electric current can remarkably affect the solidification process and microstructures of immiscible alloys. The solidification techniques under the effects of electric and magnetic fields have great potentials for the fabrication of immiscible alloys. This paper reviews the research work in this field in recent years.     

Application of dendrite fragmentation to fabricate the homogeneous dispersed structure in undercooled Cu-Co immiscible alloy

The dependence of microstructure on undercooling for Cu₅₀Co₅₀ immiscible alloy and the relations between dendrite fragmentation and liquid phase separation were studied by melt-fluxing in combination with cyclic superheating. It is shown that homogeneous dispersed structure can be obtained by dendrite fragmentation because of the increased solute content in primary dendrite, which is advantageous for strengthening dendrite remelting effect and thermal plateau time following recalescence. As for the sample after liquid separation, typical dual-layer structure forms, while dendrite fragmentation still exists and its extent, volume fraction are influenced by the solute contents of two immiscible layers. Quantitative thermodynamic calculation was further performed to support the experimental results.     

难混溶合金及其制备技术研究进展

综述了难混溶合金在微重力和地面条件下制取具有均匀弥散相结构的研究成果。指出了形核、生长-扩散-对流／扩散、重力造成的沉积或上浮、相间界面能、Ostwald熟化、Marangoni运动、Brownian凝并、第二相含量和冷却速度等影响难混溶合金凝固的各种因素，分析了难混溶合金在定向凝固过程中从纤维型规则复合组织到规则排列的串状组织再到弥散分布粒子的组织演变现象。根据难混溶合金的凝固特点，介绍了粉末冶金法、定向凝固法、模拟微重力熔融铸造法、搅拌铸造法、快速凝固法等几种不同特点的制备技术。总结了密度动态法、分离粒子法、相场法等计算机组织模拟方法在难混溶合金方面的应用，同时指出了难混溶合金研究存在的问题和今后的研究方向。     

Liquid phase separation and microstructure characterization in a designed Al-based amorphous matrix composite with spherical crystalline particles

The solidification process of the immiscible alloys exhibit a unique opportunity in designing the composites with the spherical crystalline particles dispersed in the amorphous metal matrix. The typical Al–Pb immiscible alloy and the additional elements Ni, Y and Co were selected, and the Al_82.87Pb_2.5Ni_4.88Y_7.8Co_1.95 multicomponent immiscible alloy has been designed. The ribbon samples of the multicomponent alloy were prepared by using the melt spinning technique. The ribbons were characterized by the scanning electron microscopy (SEM). The phase constitution and transformation were studied by the X-ray diffraction (XRD) and the differential scanning calorimeter (DSC). It was revealed in the as-quenched ribbons the Al-based metallic glass matrix is embedded by the spherical crystalline Pb-rich particles. The microstructure evolution, the glass formation and the thermal stability of the as-prepared composite have been discussed in detail. A method has been developed based on the mechanism of the liquid–liquid phase transformation in the miscibility gap of the multicomponent immiscible alloy to produce the spherical crystalline particles in the amorphous matrix.     

INVESTIGATION OF RAPID DIRECTIONAL SOLIDIFICATION OF AL-BASED IMMISCIBLE ALLOYS Ⅱ. EFFECT OF THE THIRD ELEMENT

对Al-Bi基难混溶合金添加第三组元Si和Cu,揭示了Si和Cu含量对Al-Bi合金快速定向凝固组织的影响.结果表明,添加Si或Cu均使凝固组织中的富Bi粒子尺寸增大;在相同的实验条件下,元素Si比Cu更易使富Bi相粗化.分析了第三组元对二元合金体系的自由能、两液相间界面能和液相粘度的改变及其对合金凝固过程的影响,加深了对三元难混溶合金凝固特征的认识.     

Model for calculation of microstructural development in rapidly directionally solidified immiscible alloys

A model has been developed for the calculation of the microstructural evolution in a rapidly directionally solidified immiscible alloy.Numerical solutions have been performed for Al-Pb immiscible alloys.The results demonstrate that at a higher solidfication velocity a constituteional supercooling region appears in front of the solid/liquid interface and the liquid-liquid decomposition takes place in this region.A higher solidification velocity leads to a higher nucleation rate and ,therefore,a higher number density of the minority phase droplets.A s a result,the average radius of droplets in the melt at the solid/liquid interface decreases with the solidification velcity.